METHODS FOR FORMING NMOS EPI LAYERS

摘要

NMOS transistors having controlled channel strain and junction resistance and methods for the fabrication of same are provided herein. In some embodiments, a method for forming an NMOS transistor may include (a) providing a substrate having a p-type silicon region; (b) depositing a silicon seed layer atop the p-type silicon region; (c) depositing a silicon-containing bulk layer comprising silicon, silicon and a lattice adjusting element or silicon and an n-type dopant atop the silicon seed layer; (d) implanting at least one of the lattice adjusting element or the n-type dopant which is absent from the silicon-containing bulk layer deposited in (c) into the silicon-containing bulk layer; and (e) annealing the silicon-containing bulk layer with an energy beam after implantation in (d). In some embodiments, the substrate may comprise a partially fabricated NMOS transistor device having a source/drain region defined therein.